Fix converting large Integers to python ints

Author: isuruf

symengine/lib/symengine_wrapper.pyx

@@ -1722,7 +1722,7 @@ class Integer(Rational):
             return sage.Integer(str(self))
 
     def __int__(Basic self):
-        return symengine.mp_get_si(deref(symengine.rcp_static_cast_Integer(self.thisptr)).as_integer_class())
+        return int(str(self))
 
     @property
     def p(self):

symengine/tests/test_number.py

@@ -15,8 +15,10 @@ def test_integer():
 
 
 def test_integer_long():
-    i = Integer(123434444444444444444)
-    assert str(i) == "123434444444444444444"
+    py_int = 123434444444444444444
+    i = Integer(py_int)
+    assert str(i) == str(py_int)
+    assert int(i) == py_int
 
 
 def test_integer_string():